Enu mutagenesis screen for epigenetic modifiers in the mouse

We have used an ENU mutagenesis screen in FVB/NJ mice carrying an epigenetically sensitive GFP transgene (designated Line3) to identify genes involved in transgene silencing. The GFP transgene is only expressed in erythrocytes and mice with mutations in genes affecting GFP expression were identified by a shift in the percentage of erythrocytes expressing GFP. Mutants were crossed with wild-type Line3 mice, homozygous for the transgene, for at least six generations, and mutations located by whole exome sequencing.